A biennial or short-lived perennial, the western wallflower (Erysimum capitatum) is a variable plant. The flowers range from orange to bright yellow and can even be maroon or white. At lower elevations western wallflower grows between 1 and 3 feet in height with narrow leaves that are 3 to 6 inches long. At higher elevations this member of the mustard family grows only 4 or 5 inches tall. On Alpine slopes the leaves from one year die back and protect the root crown from which the stem emerges the following year – an adaptation to the short growing season and long, harsh winters.
The preferred habitat of western wallflowers are stony slopes and swales. A native, this wallflower can be found in much of Western United States, Alaska as well as regions of the Midwest and Central portion of the Eastern Seaboard.
The western wallflower’s inflorescence is a round-topped cluster of four-petaled Maltese cross-shaped flowers. The leaves are alternate, lance-shaped and usually toothed. The silique (pod-like fruit of some mustard plants) is narrow and grows nearly vertically along the stem. There are no indentations on the silique between the seeds.
Western wallflowers are not commonly used for medicinal or culinary purposes. However, wallflowers are attractive to butterflies.
David Douglas collected the first specimens of E. capitatum and therefore this plant is often called Douglas’ wallflower. Other common names for E. capitatum are sanddune wallflower and prairie rocket, among others.
The genus name, Erysimum, comes from the Latin word “erysio” meaning “to draw” (i.e. draw out pain) or “to cause blisters”. Some members of this genus are used as poultices. The species, capitatum, “head” in Latin, probably refers to the head-like shape of the inflorescence or the shape of the stigma.
These western wallflowers were growing near Eskimo Hill (CA Highway 89) .